Electrical terminal



Jupel5,193T

R. N. Rows 2,083,923

ELECTRICAL TERMINAL Filed March 3, 1934 INVENTOR Patented June '15, 1937I Raymond N. Rowe, Plainville,

Conn, assignor to The Trumbull Electric Manufacturing Company,Plainville, Conn, a corporation of Connecticut Application March a,1934, Serial No. 713,788

3 Claims.

My invention relates particularly to what are frequently termedsolderless wire lugs or terminals.

The main object is to provide a simple in- 5 expensive form ofconstruction for aifording effective electrical connection.

A special object is to provide a form of device suited for receivingmulti-wire cables of the stranded type.

One of the objects is to-provide a construction in which such a cablecan be readily secured and effectively held.

Another object is to provide a construction which will provide aparticularly effective electrical connection.

In carrying out the invention I provide a terminal preferably of onepiece including an anchorage plate or base and a housing or body inwhich the cable end is secured. This housing is provided with a passageor recess forming a socket adapted to receive the end of the cable. Thebottom of this socket is V-shaped or provided with tapered sides and aclamp screw or nut which is screwed into the body engages the cable andjams it tightly into the bottom of this V-shaped notch. At the same timethe cable is spread so as to prevent accidental withdrawal.

Theclamp nut is provided with a series of B0 concentric ribs and groovesby means of which effective electrical connection is provided and thewires of the cable end are compacted and snugly held. Fig. 1 is anexploded perspective view of the 55 parts of the device embodying myinvention.

Fig. 2 is a cross sectional view on the plane of the line 2-2 of Fig. 3,part of the wires of the cable being omitted to show the interiorconstruction of the socket.

Fig. 3 is a sectional view on the plane of the line 33 of Fig. 2 withthe wire ends in place.

Fig. 4 is a sectional view on the same plane as Fig. 3 but omitting thecable end. 55 Fig. 5 is a view of the underside of the clamping nut orscrew.

The base i may be of any suitable form and provided with any suitablemeans of securing it to the usual support. n The main body 8 of theterminal is preferably integral with the plate vided with a recess or.socket 9 adapted to'receive the end of the cable m.

A screw threaded recess H intersects the ca socket 9 and is adapted toreceive the clamp portion 1 and is proscrew or nut l2. The body and theclamp screw are preferably so designed that the clamp screw will notproject above the top of the housing when the device is in use. Thisleaves a smooth upper surface-and has all the advantages of typicalcounter-sunk safety set screws and the like.

The socket 9 extends beyond the recess 'M to form a pocket l3 for thetip end of the cable. The bottom of the threaded recess ll is below thetop of the socket 9 so that in efiect lateral extensions or bays It areprovided into which the cable may be expanded when the clamp screw isset up against it.

The bottom of the socket 9 is notched or V-shaped at l5 so thatinclined. sides are provided which coact with the sides of the cablewires when the clamp screw is set in tightly. Some of the wires are thusjammed out into the bays I4 as shown in Figs. 2 and 3.

The bottom of the screw plug is provided with a series of concentricribs l6 as shown in Figs. 2 and 5 which act as teeth to cut into orindent the wires of the cable and assist in providing an effectiveelectrical connection. They also tend to hold together the top wireswhile the central 1 wires are being spread laterally as shown at 11,

thus providin an effective mechanical connec- 1 tion as well as aneffective electrical connection.

As previously explained, part of the wires are omitted from Fig. 2 ofthe drawing for the purpose of showing the interior construction of thesocket but practice, the wires of the cable are forced outwardly andequally on both sides of the center line so as to fill the wirereceiving portion of the socket. 1

It will thus be seen that the "construction is simple and inexpensiveand yet effective from an electrical as well as a mechanical standpoint.The cable end can be readily inserted and secured without soldering andyet it can be removed if necessary when desired.

The construction also effectively clamping wires or cables of erablerange of sizes or diameters.

A noteworthy feature 'of this connector resides in the attainment of atight gripping contact and one feature contributing to this result isthe ability of a multi-wire cable to be deformed transversely in threedifferent directions, downwardly between the converging sides of thesocket and also laterally into the pocket on each side of the cable. Theconverging sides of the socket are shown in the drawing as beingconvexly curved to provides a means for a considit will be readilyunderstood that, in y assist in this deformation or flow of the wires ofthe cable in the different transverse directions. The plurality ofconcentric ridges on the contacting or lower face of the clamp screw areshown in the drawing as being adapted to engage and grip a large numberof the wires of a cable in a number of places, irrespective of theangular position of the clamp, and at the same time these ridges are notso deep as to substantially impede the transverse deformation of theconductor.

I claim:

1. An electrical connector including a body provided with a wirereceiving recess, a clamping member for cooperation with a wire forholding the same in said recess, the recess being laterally enlargedintermediate its ends to form pockets and allow a stranded conductor tobe expanded laterally within said recess asit is compressed by saidclamping member, whereby opposite sides of such a wire may be bent inopposite directions, the wall of said recess opposite the clampingmember and between said pockets being of V shape with the sides of the Vconvexly curved.

2. A solderless electrical connector having a solid metal body with arecess for receiving a substantially cylindrical cable formed ofmultiple strands, a substantial portion of the wall of the 'recess beingcylindrical to conform to the cable end and the remainder of the wallhaving sides inclined at approximately ninety degrees with respect toeach other, said body having a screw threaded passage intersecting therecess, said passage being of larger diameter than the recess and aclamp screw adjustable in said passage and having a bearing surfacewhose general plane is transverse to the passage, said recess having aV-shaped channel between the side walls beneath the screw so that whenthe screw is tightened on the cable in the recess strands are forceddownwardly in the V-shaped notch and spread laterally in the bottom ofthe sides of the screw recess.

3. A solderless electrical connector having a solid metal body with arecess for receiving the end of a substantially cylindrical cable formedof multiple strands, a part of the wall of the recess beingsubstantially cylindrical to conform to the cable end and a substantialpart of the wall having channelled sides inclined toward each other withan inclined angle of at least about ninety degrees between the sidewalls, said body having a screw threaded passage intersecting saidrecess, said passage being of larger diameter than the recess and aclamp screw adjustable in said passage and having a generally fiatbearing surface with a plurality of sharp concentric ridges so'that whenthe screw is tightened on the cable in the recess some of the strandsare forced into the sides of the passage. I

RAYMOND N. ROWE.

